from rest_framework import serializers
from models         import EventParticipation




class ParticipationSerializer(serializers.ModelSerializer):
    event  = serializers.PrimaryKeyRelatedField( many=False, read_only = False )
    user   = serializers.Field( source='get_username' )
    
    def get_identity(self, data):
        """  This hook is required for bulk update.   """
        try:
            return ( data.get('event', None), data.get('user') )
        except AttributeError:
            return None

    class Meta:
        model = EventParticipation
        fields = ('event', 'user', 'status', 'comment')